This proposal is to develop a rapid serodiagnostic and accurate confirmatory test for detection of Trypanosoma cruzi infections built on a set of novel recombinant antigens. This parasite is transmitted via blood transfusion, is prevalent in Latin America, and is the causative agent for fatal Chagas' disease. Positive blood donors have been identified, and transmission via the insect vector has been reported in the U.S.A. Current methods to detect infection involve serological screening using whole parasites, or crude lysates and confirmation tests in the U.S.A use a complex radioimmunoprecipitation (RIPA) assay. In this proposal, we have used TcF that contains four different repeating epitopes, as the central diagnostic target antigen. We have identified and characterized additional antigens to complement TcF using sera that were non or low reactive with confirmed T. cruzi infection sera. These antigens include recombinants and peptides such as His- 1.1, 1.2, SAPA, Peptide 30 and 36. We will continue to identify additional antigens via serological expression cloning using low titer/RIPA confirmed and TcF low or non-reactive sera from U.S.A. blood donors and from different regions of Central America. This proposal details the development of a rapid inexpensive test for the diagnosis of T.cruzi infections in small clinics/blood banks in Latin America or in diagnosing T. cruzi infections in prospective U.S.A. cardiac surgery patients with high risk factors for Chagas' disease and a confirmatory immunoblot assay for use in the U.S.A blood banks. These studies will exploit the expertise of InBios to develop rapid tests in combination with Corixa TcF antigen. The studies will also benefit from a close collaboration with renowned consultants and collaborators and access to their serum bank.